1. Field of the Invention
This invention relates in general to computer-implemented data warehouse systems, and in particular, to a computer-implemented scalable data warehouse architecture.
2. Description of Related Art
Databases are computerized information storage and retrieval systems. A Relational Database Management System (RDBMS) is a database management system (DBMS) which uses relational techniques for storing and retrieving data. Relational databases are organized into tables which consist of rows and columns of data. The rows are formally called tuples. A database will typically have many tables and each table will typically have multiple tuples and multiple columns. The tables are typically stored on random access storage devices (RASD) such as magnetic or optical disk drives for semi-permanent storage.
RDBMS software using a Structured Query Language (SQL) interface is well known in the art. The SQL interface has evolved into a standard language for RDBMS software and has been adopted as such by both the American National Standards Institute (ANSI) and the International Standards Organization (ISO).
In RDBMS software, all data is externally structured into tables. The SQL interface allows users to formulate relational operations on the tables either interactively, in batch files, or embedded in host languages, such as C and COBOL. SQL allows the user to manipulate the data.
The definitions for SQL provide that a RDBMS should respond to a particular query with a particular set of data given a specified database content, but the method that the DBMS uses to actually find the required information in the tables on the disk drives is left up to the RDBMS. Typically, there will be more than one method that can be used by the RDBMS to access the required data. The RDBMS will optimize the method used to find the data requested in a query in order to minimize the computer time used and, therefore, the cost of doing the query.
Today, a DBMS can instead be an object-oriented database management system (OODBMS). An object-oriented database is organized into objects having members that can be pointers to other objects. One of the key features of an OODBMS is the ability to navigate between objects using these pointers. Additionally, an object can have relationships to other objects. The objects contain references, and collections of references, to other objects in the database, thus leading to databases with complex nested structures.
In conventional relational or object-oriented database systems, a client computer is connected to a server computer. The server computer is connected to a data storage device holding a database. When a user desires to obtain data from the database, the user inputs a request for data at the client computer. The client computer transmits the request to the server computer, which retrieves the requested data from the database. The server computer transmits the retrieved data to the client computer. Next, the client computer provides the data to the user. However, as computers are connected in more complicated networks, this is an inefficient manner of retrieving data. There is a need in the art for an improved method of retrieving data when computers are connected in complicated networks.